Re: [PATCH 2/3] string: Fix bug-strncat1 with fortify enabled

[Siddhesh Poyarekar <siddhesh@gotplt.org>]

On 2023-07-24 10:26, Adhemerval Zanella Netto wrote:
> 
> 
> On 24/07/23 11:24, Siddhesh Poyarekar wrote:
>> On 2023-07-24 08:36, Carlos O'Donell via Libc-alpha wrote:
>>> On 7/21/23 08:18, Adhemerval Zanella via Libc-alpha wrote:
>>>> If fortify is enabled, the truncated output warning is issued by
>>>> the wrapper itself:
>>>>
>>>> bug-strncat1.c: In function ‘main’:
>>>> bug-strncat1.c:14:3: error: ‘__builtin___strncat_chk’ output truncated
>>>> copying 1 byte from a string of length 2 [-Werror=stringop-truncation]
>>>>      14 |   strncat (d, "\5\6", 1);
>>>>         |   ^
>>>>
>>>
>>> I find it suspect that this triggers on line 14, but given that the whole
>>> test is intended to test truncated output, we should disable this warning
>>> for the whole file.
>>>
>>> LGTM.
>>>
>>> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
>>
>> In that case, wouldn't it be better to patch the Makefile instead?
> 
> My understanding of using libc-diag.h is a having an explicit mark with
> additional comment so we can safely remove the suppression if/when we
> move the minimum supported compiler.
> 

OK fair enough.

Thanks,
Sid